Comprehensive and representative conservation planning for biodiversity of ice-free Antarctica.

Antarctica is designated as a natural reserve devoted to peace and science, with Antarctic Specially Protected Areas (ASPAs) serving as the primary instrument for area-based biodiversity protection. However, the existing ASPA network lacks the comprehensiveness and representativeness required under Annex V, Article 3(2), of the Madrid Protocol. We demonstrated the application of systematic conservation planning to explore the trade-offs underlying protection at a continent-wide scale, focusing on the principles of comprehensiveness and representativeness. These principles are the foundations of designing an effective protected area system that ensures all biodiversity features and their diversity are captured. We investigated how systematic conservation planning applies in the Antarctic and evaluated the impact of alternative species targets and cost measures on performance and area selection. We found that cost assumptions had a greater influence than species target formulation on spatial priorities, and access costs based on proximity to research stations systematically disadvantaged remote species. Furthermore, our results demonstrated that comprehensive and representative protection could be achieved by balancing the placement of protected areas at varying distances from research stations. Finally, stakeholder engagement must occur throughout the process if this approach is to be formally undertaken through the Antarctic Treaty System.